identifying andersen window balance spring

Question

I need replacements for these Old parts. The windows no longer have identification on them so I am unsure the glass type or I would look up the dimensions. After 2 hours I found no trace of these part numbers anywhere.

E15 8 31 171 (maybe L71?)
E18 8 31 272
E2 9 31 473

Tom · Accepted Answer

Hello! The key stamps here are "8 31," "8 31," and "9 31." The other numbers in each stamp can be safely ignored.

With that in mind my recommendation would be the 24-837 for the first two and the 24-939 for the second two. These Andersen brand balances are designed to replace those respective stamps.

Please let me know if you had any other questions!